1. Field of the Invention
The present invention relates to a temperature sensing apparatus and a method of sensing temperature, and relates more particularly to a temperature sensing apparatus disposed in a chip and a method of sensing temperature.
2. Description of the Related Art
The performance of integrated circuits is usually affected by the temperature of their internal components. Thus, many temperature-sensing circuits are extensively used in integrated circuits to measure the internal temperatures of the integrated circuits. FIG. 1 is a block diagram illustrating a conventional temperature sensing circuit 10. Referring to FIG. 1, the temperature sensing circuit 10 comprises a voltage generation circuit 12 configured to generate a voltage VPTATA that varies with changes in temperature and a voltage-to-frequency converter 14 configured to receive the voltage VPTATA to generate a frequency signal fPTAT. Because the voltage VPTATA varies linearly with the variation of temperature, the frequency signal fPTAT changes according to the variation of temperature.
In the conventional circuit, a crystal oscillator (not shown) counts the pulse number of the frequency signal fPTAT. The crystal oscillator is an external component that increases cost and needs an installation area. Further, an extra pin is needed on the chip to connect with the crystal oscillator. Thus, electronic industries need a temperature-sensing device that can be disposed in a chip to mitigate the above issues.